Method of making inflatable fabric lined rubber articles



S p 1954 R. R. MoLLlcA ET AL METHOD OF MAKING INFLATABLE FABRIC LINEDRUBBER ARTICLES Filed June 24, 1952 .ATIORNEY Patented Sept. 21, 1954METHOD OF MAKING INFLATABLE FABRIC LINED RUBBER ARTICLES Russell R.Mollica, Cranston, and Helen T. Sweet,

Johnston, R. I., assignors to United States Rubber Company, New York, N.Y., a corporation of New Jersey Application June 24, 1952, Serial No.295,372

This invention relates to a method of forming inflatable fabric linedrubber articles and in particular to articles of this type which have aninternal tubular construction in which the tubes are freelyintercommunicating.

Inflatable articles having a tough impervious outer surface of rubber orother suitable material are made in great quantities for a variety ofpurposes. Frequently these articles are made having an internal fabriclining of duck or other sturdy fabric to make the articles more durablein use, and when so constructed the articles have almost unlimited usein applications in which a sturdy construction is required, and whichcan be collapsed within a small compass so that it may be stored ortransported easily when it is not in use. Articles made of thisconstruction are suitable for such varied uses as water toys,collapsible boats, wading pools, portable tubs, etc.

It is an object of this invention to provide a method by which sucharticles may be made with a minimum number of operations that areextremely simple to perform, so that great savings in manufacturingcosts may beachieved. More specifically this invention contemplates amethod in which a sheet of fabric which is to form the lining for theinflatable article is doubled upon itself and sewed together along theunfolded edges of the fabric. A sheet of rubber or other suitablecovering is applied to each exterior side of the folded fabric whenflat, and the two covering sheets are joined to each other byoverlapping joints beyond the boundaries of the folded fabric so thatthe fabric is entirely enclosed in the covering.

Although many of the advantages of this invention may be had when it isused to produce articles in which the folded fabric is sewed together atits edges only, the method has special advantages when used to makeinflatable articles which are formed with a series of tubes extendingthrough the article. Thus, for example, collapsible boats are madehaving a rubber bottom and inflatable sidewalls which are formed in aseries of parallel tubes extending about the entire periphery of theboat. The side walls are given a tubular construction to providerigidity when inflated, to economize on the material which is used toform the sides, and to provide the inflated boat with comparatively thinupstanding walls. Such walls may be made quite simply by the method ofthis invention, for a piece of fabric approximately equal in length tothe desired periphery of the boat walls may 3 Claims. (Cl. 154-85) befolded transversely on itself and the folds sewed together lengthwise atspaced intervals so that seams are formed which will define the desiredparallel tubes between adjacent seams. Before forming the tubes the endsof the fabric may be sewed together to form a closed loop, and after thetubes are formed the fabric is covered as described above. There willthus be formed an inflatable wall having a continuous parallel tubularconstruction in which the individual tubes intercommunicate freely alongthe entire length of the seams through the interstices between adjacentthreads in the seam. Thus the walls may be inflated easily, for when airpressure is applied to any one of the tubes the entire wall will beinflated.

The method of this invention is very flexible, and the details ofmanufacture of articles by this method may be varied to produce articleshaving varied characteristics. Thus in inflatable boats and otherarticles it is frequently found desirable to have a somewhat differenttubular construction at various points on a single article. For example,it may be desirable to have boat walls constructed so that at oneportion thereof, for example the stern, they will have 3, 4, or moreparallel tubes, yet at another portion of the wall such as the bow only2 or 3 parallel tubes may be desired. When such a construction isdesired it may be formed according to this invention by interrupting orresuming during the sewing operation one or more of the stitched seamsat the required points about the periphcry of the walls, or the seam maybe interrupted and resumed at a point which is shifted laterally fromthe interrupted seam to produce the construction desired in the finishedarticle.

For a better understanding of the nature of this invention and of themeans by which its many advantages are achieved, reference should be hadto the following description in which a specific embodiment thereof isdescribed as applied to the making of an inflatable wading pool, and tothe illustration of the construction of such a pool shown in theaccompanying drawing, wherein:

Fig. 1 is a plan view of a portion of the folded fabric after the foldshave been stitched together to form the parallel tubes, and the endshave been stitched together to form a closed loop;

Fig. 2 is an enlarged sectional View along the line 22 of Fig. 1 of thefabric but having the sheets of impervious material applied to theoutside of the fabric;

Fig. 3 is a perspective view of the completed Wading pool when it hasbeen inflated; and

Fig. 4 is a sectional view of the inflated walls taken through theinflating valve along the line 4& and of a portion of the bottom of thewading pool.

Referring now to the drawing, to form a wading pool according to themethod of this invention a piece of duck or other sturdy fabric It whichis to form the lining for the rubber walls is cut to a shape required toproduce the article desired. For the wading pool shown, this fabric Hiis cut to rectangular shape having a length approximately equal to thecircumference desired in the wading pool and having a width large enoughto produce the required height when the fabric is folded longitudinallyupon itself and inflated as desired in the finished article.

To form the loop of the walls of the wading pool the ends I! and E2 ofthis fabric ID are overlapped and joined together by stitching a seam itacross the entire fabric. The fabric loop is then folded upon itselflengthwise of the fabric at the middle 14 thereof to form a double plyfabric the plies at which have their longitudinal edges 25 adjacent eachother.

The two plies which are thus formed by the folding of the fabric arethen made into a flat sleeve by joining the plies together near theedges iii of the fabric by stitching a seam l5 about the looped fabric.To form the tubular construction in this sleeve the folds of the fabricare joined together at spaced points by stitching additional parallelspaced apart seams ll about the looped folded fabric Hi. The fabric H3may then be coated with a suitable cement, or it may have been so coatedpreviously, and a sheet of impervious material l8 of rubber or othersuitable material is applied to one side of the flat folded fabric. Thecement serves to bond the impervious sheet l8 firmly to the fabric itthroughout the contacting areas of the fabric and coating. Thisimpervious material has a length suflicient to extend entirely aroundthe loop of the fabric and a width such that it will completely coverthe fabric and extend over the edges thereof to form flanges it, for apurpose to be described. A second sheet of impervious mtaerial I8 isapplied to the other side of the flat folded fabric. This. second sheetof impervious material has a length and width similar to the first sheetso that after the application of both sheets to the folded fabric It, itis entirely enclosed in the impervious material. Thus the fabric Illwill line the entire rubber article when it is inflated. The flanges E9of the first sheet it of impervious material which extend beyond theedges of the fabric are bonded to the similar flanges of the secondsheet to form flange seams to close the walls so that only that portionof the wall which is lined with the fabric is may be inflated. A bottom20 for the wading pool of rubber or other suitable material is thenapplied over one of the ends of the loop of covered fabric to form thecompleted wading pool. An inflating air valve 2| is applied in the usualmanher to the walls of the wading pool at any desired point. Since inmaking the article the impervious coatings !8 have been applied afterthe sewed seams it and ii are formed, external leakage of air throughthe seams will not occur.

Other articles may be made by the above described process by suitablyvarying the manufacturing procedure to produce an article having thecharacteristics desired. Thus an inflatable boat would be made bysubstantially the above described process, but the fabric if] and sheetsof impervious material [8 would be selected having such a length aswould be required for the periphery of the boat walls. Similarly thebottom of the boat would be out to the desired boat outline. To form asurfboard water toy, the procedure would be varied by omitting the stepof joining the ends of the fabric before it is folded. These ends wouldbe cut to a suitable shape for the surfboard and, when folded, thefabric would be stitched about its edges, and the parallel seams wouldbe stitched therein to form the tubes. An inflatable mattress could besimilarly formed.

Although many specific procedures may be used for making inflatablefabric lined articles according to this invention the following is asatisfactory procedure for making the wading pool illustrated in thedrawing. A duck fabric is coated on one side with a suitable adhesive,and then cut to correct width and length. The ends of the fabric arethen stitched together to form a closed loop, and the looped fabric isfolded to form a circular sleeve having the coated side exposed. Thenequally spaced compartments which are to form the tubes are made bystitching the folds together with nylon thread in substantially parallelseams running about the looped fabric. The use of nylon thread for thestitching is desirable because it is a stronger.

thread, so that when'the nylon thread is used with a duck fabric theinflated article may be capable of withstanding greater inflatingpressures; and also because nylon thread stretches, so that wheninflating pressures are applied to the article these threads willelongate somewhat to permit the walls of the article to part slightly atthe stitching to facilitate further the inflaion of the article from asingle air valve. The sewn sleeve is then placed on a building form,which when the article to be made is a wading pool would be a drum typeform having a flat end and cylindrical sides. A sheet of neoprene gum isapplied to one side of the sleeve, and the sleeve is then reversed onthe building form and a second sheet of neoprene gum is applied to theopposite side of the sleeve making the flange seams described above withthe first sheet of gum. The bottom 29 is then laid over the end of thedrum and aproximately one inch of the inflatable side wall is turneddown over the base of the drum and adhered to this bottom 20. Thearticle is then removed from the building form, turned inside out andplaced on a similar curing form and cured in the usual manner. After thearticle has been cured an air valve is applied to the inflatable wallsin the usual manner to produce the completed wading pool shown in Figs.3 and 4 of the drawing.

Having thus described our invention, what we claim and desire to protectby Letters Patent 1s:

1. The method of forming a fabric-lined rubber pool having inflatablewalls with a parallel tubular construction which comprises, applying anadhesive to one face of a rectangular sheet of a woven fabric, stitchingthe ends of the fabric together to form a closed loop, folding thefabric upon itself to form a sleeve having the adhesive exposed,stitching the edges of the fabric together, sewing additionalsubstantially parallel seams of strong and stretchable threads throughthe folded fabric to form a plurality of tubes in the sleeve whichintercommunicate through the interstices of the seams, applying a rubbercoating to both sides of the flat stitched fabric to completely enclosethe fabric in rubber, and applying a liquid impervious bottom over oneend. of the fabric to close the loop and form a pool.

2. The method of forming an inflatable fabriclined article whichcomprises folding a piece of fabric upon itself, stitching the foldedfabric to itself along a seam to form a pocket Within the fabric bonded.by the fold line and the seam, applying a sheet of air and liquidimpervious material to each exterior side of the fiat folded fabric toenclose the fabric and to form flange joints with each other beyond theedges of the fabric, and applying an adhesive to the exterior face ofthe fabric which is to receive the sheets of impervious material beforeapplying the impervious material.

3. The method of making an inflatable fabriclined rubber article formedof a plurality of distinct intercommunicating tubes, which comprisesfolding a piece of duck fabric upon itself, sewing parallel spaced apartseams in the folded fabric to join the fabric to itself along spacedapart seams, applying a sheet of neoprene gum to each exterior side ofthe flat seamed fabric to enclose the fabric and to form flange jointswith each other beyond the edges of the fabric, and applying a cement tothe exposed face of the fabric at any time before applying the sheets 10of neoprene gum to the fabric.

References Cited in the file of this patent UNITED STATES PATENTS2,408,789 Luisada Oct. 8, 1946

1. THE METHOD OF FORMING AN INFLATABLE FABRICLINED ARTICLE WHICHCOMPRISES FOLDING A PIECE OF FABRIC UPON ITSELF, STITCHING THE FOLDEDFABRIC TO ITSELF ALONG A SEAM TO FORM A POCKET WITHIN THE FABRIC BONDEDBY THE FOLD LINE AND THE SEAM, APPLYING A SHEET OF AIR AND LIQUIDIMPERVIOUS MATERIAL TO EACH EXTERIOR SIDE OF THE FLAT FOLDED FABRIC TOENCLOSE THE FABRIC AND TO FORM FLANGE JOINTS WITH EACH OTHER BEYOND THEEDGES OF THE FABRIC, AND APPLYING AN ADHESIVE TO THE EXTERIOR FACE OFTHE FABRIC WHICH IS TO RECEIVE THE SHEETS OF IMPERVIOUS MATERIAL BEFOREAPPLYING THE IMPERVIOUS MATERIAL.